#include
    
     #include
     
      #include
      
       using namespace std;const int N=500005;struct node{    int left,right,val,start,id;    bool operator <(const node &x)const{return x.val>val;}}dp[N][40];priority_queue
       
        q;int n,k,l,r,a[N],sum[N],log[N];long long ans;inline void pre_st(){    log[1]=0;    for(int i=2,t=1;i<=n;i++)    {        while((1<
        
         <=i)t++;        log[i]=t-1;    }    for(int i=1;i<=n;i++)dp[i][0].val=sum[i],dp[i][0].id=i;    for(int j=1;(1<
         
          <=n;j++)for(int i=1;i+(1<
          
           <=n;i++) if(dp[i][j-1].val
           
            <<(j-1))][j-1].val)dp[i][j]=dp[i+(1<<(j-1))][j-1]; else dp[i][j]=dp[i][j-1];}inline node query(int x,int y){ int m=log[y-x+1]; if(dp[x][m].val
            
             <
             
              rr) return; node sub=query(ll,rr); sub.val-=sum[head-1],sub.left=ll,sub.right=rr,sub.start=head; q.push(sub);}int main(){ ios::sync_with_stdio(false); cin>>n>>k>>l>>r; for(int i=1;i<=n;i++)cin>>a[i],sum[i]=sum[i-1]+a[i]; pre_st(); for(int i=1;i<=n;i++) { if(i+l-1>n)continue; int l1=min(n,i+l-1),r1=min(n,i+r-1); pus(l1,r1,i); } while(k--) { node now=q.top(),nex,ney; q.pop(); ans+=now.val; pus(now.left,now.id-1,now.start); pus(now.id+1,now.right,now.start); } cout<
              
               <